The present invention particularly relates to a method for determining the condition of an animate or an inanimate object which condition can be evaluated by providing information on time dependent effects which are either induced or spontaneous. For example, in a solid body which is not of a biological type, the perfusion of a gas or a liquid which is fed under certain condition can be observed by MRI, such as by acquiring a sequence of images in which each image is acquired at a different time within a certain time period. Structural modifications relating to a change in physical or chemical parameters can be observed, such as, for example, temperature dependent structural changes in solid bodies which are subjected to temperature which varies over time by heating or by cooling or structural changes which are induced by mechanical stress that is exerted on a body, or structural or chemical changes that are induced by exposure to radiation in which the intensity or dosage changes with time, structural or chemical changes which occur due to the application of chemical substances to the body that are interacting with the substance or the material of which the body is made.
Such time dependent effects may be observed by carrying out an MRI session of the body in which an image is acquired at predetermined time intervals. In this way, the time dependent changes in parameters of the image may be empirically determined, for example, time dependent changes of the mean intensity of the image or of only a partial area of the image.
In many cases, particularly in cases in which MRI is applied for diagnostic purposes, the pathological condition of in vitro or living tissues is a time dependent activity or one which can be best appreciated by using induced mechanisms in the tissue which are time dependent. This means that in order to isolate or to identify the condition of the object it is necessary or preferable to carry out a sequence of images, with each image being acquired at certain different times within a certain time interval.
Particularly relevant is the case for isolating and identifying and evaluating pathologic conditions such as infections and/or tumors, or the like. It is known that vascularisation is enhanced in regions in which tumoral cells are present or in which there is an infection. Thus in this case in order to isolate and identify such conditions it is known to evaluate the increase of vascularisation by means of contrast media perfusion measurements.
Perfusion measurements conducted with MRI are usually carried out by acquiring a sequence of images of a selected anatomical region or tissue region after a contrast media has been injected into the region. Contrast media are transported by the blood and the speed of transport of diffusion of the contrast media in the tissue or anatomical region of interest is used for evaluating vascularisation. The mean intensity of the imaged region of interest is then determined from the image data of each image of the sequence and a so-called “perfusion curve” is constructed from the data pairs, the mean intensity of the region of interest of each one of the images of the sequence of images, and the time of acquisition of the images.
By comparing the perfusion curve with other perfusion curves which are uniquely related to known clinic cases or tissue conditions, it is then possible to determine some indications on the clinical condition of the imaged tissue or anatomical region.
This evaluation has been carried out until now in a non-systematic way.
Thus there is the need for providing for a method of determining a condition of an object, particularly the pathological condition of living or in vitro tissues which is much more reliable and which is integrated in a well defined manner and which automatically determines the indications about the probable pathological condition of an object under examination which pathological condition is unknown.
The invention therefore has the aim of providing a method for determining the condition of an object by MRI.
The invention is directed to providing a method enabling one to have unique criteria so that measurements carried out by different subjects and different devices can be reliable and comparable, thus permitting a widespread exchange of data between different subjects which carry out the examination and evaluate the results.
Another goal of the present invention is to reduce the uncertainties related to the skill involved in carrying out such examinations and in visually comparing and interpreting the results.